Pneumovesical Ureteric Reimplantation in Pediatric Patients: An Intermediate Term Result

Introduction

Disease process involving the vesicoureteric junction is a common problem in pediatric urology practice. Vesicoureteric reflux (VUR) and vesicoureteric junction obstruction (VUJO) comprise the majority of this condition. Ureteric reimplantation remains the definitive treatment for patients with VUJO. Although there are different choices for the management of VUR, ureteric reimplantation serves as the ultimate option for patients who failed medical treatment or endoscopic therapy. ¹

Different surgical techniques of ureteric reimplantation have been reported, including both intravesical and extravesical approaches.^2,3 In recent years, the minimal invasive approach has become an increasingly popular alternative to traditional open ureteric reimplantation. Laparoscopic extravesical ureteric reimplantation was first described by Lakshmanan and Fung. ⁴ Later Yeung et al. reported the technique of minimal invasive intravesical cross-trigonal ureteric reimplantation using pneumovesicum with the advantage to avoid intraperitoneal complication. ⁵

Previously we have reported our early series with the first few cases of laparoscopic pneumovesical ureteric reimplantation in 2008. ⁶ Here we reviewed the results of our patients at an intermediate term basis after a decade of experience.

Materials and Methods

This is a retrospective review of all pediatric patients with pneumovesical ureteric reimplantation performed in our center between January 2005 and December 2015. Medical and operative records were retrieved for study. Patients' demographics, preoperative diagnoses, operative measures, and postoperative outcomes were extracted from the records.

All patients received either voiding cystourethrogram or MAG-3 scan before the operation to confirm their diagnosis. For VUR patients, operation was offered to those with high-grade disease (grades IV to V) or to patients with low-grade disease but presented with breakthrough urinary tract infection despite compliant to antibiotics. Patients with residual high-grade VUR or recurrent urinary tract infection after previous endoscopic injection therapy were also considered as indication for operation. Similarly, all patients with significant VUJO on MAG-3 scan were offered operation.

The pneumovesical operative technique was similar to that previously described,^5,6 which involves bladder insufflation with carbon dioxide to create pneumovesicum. After anchoring the bladder to the abdominal wall and insertion of three 5 mm step ports, the distal ureter was dissected out similar to the open Cohen method. The freed distal ureter was then brought through a submucosal tunnel created over the bladder trigone, and subsequently anchored using monofilament nonabsorbable sutures. The operative technique was similar for both VUR and VUJO patients. Patients were discharged home once they became asymptomatic with all catheters removed. After the operations, voiding cystourethrogram or MAG-3 scan was performed at 3 months interval to assess any residual or recurrent disease.

Results

A total of 31 patients were identified during the study period: 9 males and 22 females. The mean age at operation was 6.1 ± 0.6 years old (range 1–17 years). Twenty-three patients had VUR confirmed on voiding cystourethrogram, whereas 8 patients had evidence of significant VUJO on MAG-3 scan. Two VUR patients were associated with ureteroceles. Eleven patients (35%) had bilateral disease and required bilateral reimplantation. Otherwise the laterality of involvement was similar in patients with single-sided disease (Table 1).

A total of 42 ureteric reimplantation procedures were performed. The mean operative time was 221 ± 7 minutes (range 169–318 minutes). Four patients required conversion to open approach. Three of them were converted because of difficult dissection around the distal ureter, as a result of significant adhesion and fibrosis after previous endoscopic dextranomer–hyaluronic acid compound injection. Another patient was converted because of persistent air leak and failure to maintain the pneumovesicum. On average, the length of hospital stay was 7.4 ± 0.8 days (range 3–22 days). No mortality or major complication was noted. Four patients had low-grade residual VUR after the operation and all of them were treated conservatively. No recurrence of either VUR or VUJO was seen on postoperative imaging studies (Table 2).

Discussion

The development of pneumovesical ureteric reimplantation has come its long way since the end of the past century. The concept of minimally invasive approach for ureteric reimplantation was first attempted by Atala et al. in an extravesical approach on a porcine model in 1993. ⁷ However, the experience from past open surgery has warned surgeons against the potential risk to develop voiding dysfunction in patients who underwent extravesical reimplantation. In addition, the extravesical approach nevertheless carries the risk of damaging intraperitoneal structure during operation. Working in the limited pelvic space in children can also be very difficult even in a laparoscopic environment. The breakthrough did not arrive until Gill et al. reported the new technique of laparoscopic cross-trigonal reimplantation in 2001. ⁸ Yeung et al. further modified the operation with the use of carbon dioxide pneumovesicum. ⁵ It provides a better and clearer intravesical view by avoiding the fluid turbidity. A good working space can also be developed with the use of a reasonable intravesical pressure between 8 and 10 mm Hg. It also made the placement of transurethral suction catheter possible, which is an effective means to remove urine or blood from the bladder during operation.

VUR was still the main indication for ureteric reimplantation.^9,10 The best treatment approach for VUR is yet a highly debatable topic. ¹¹ Despite the wider application of endoscopic injection therapy, some patients have residual reflux with repeated injections. ¹ The low residual or recurrence rate from our data means that the pneumovesical approach is a safe alternative. Four of our VUR procedures were found to have residual disease after operation, all of them being low grade and were managed successfully with conservative treatment. Interestingly in the 4 patients who required conversion to open approach, 3 of them had history of endoscopic injection therapy. We postulated that it was the dextranomer–hyaluronic acid compound injected around the ureteric orifice previously that resulted in severe adhesion and fibrosis, making distal ureter dissection difficult and required a conversion. Pneumovesical reimplantation may, therefore, be justified as the first line treatment in patients with high-grade reflux owing to the increased operative difficulty and risks after previous endoscopic injection treatment.

The use of pneumovesical reimplantation has extended beyond its original application on VUR to include VUJO into the spectrum. There had been recent studies by Bi and Sun and Liu et al. focusing mainly on primary obstructive megaureter.^12,13 All conclusions from these studies agreed that the pneumovesical approach is as effective as the traditional open reimplantation. Bi and Sun employed the same cross-trigonal approach as we have described and the result has been highly successful with only 1 residual obstruction out of the 61 procedures performed. Liu et al. also reported improvement in more than 90% of cases. Data from our series concurred with the mentioned findings with no residual or recurrent obstruction seen in any of the VUJO patients after the operation.

In conclusion, pneumovesical ureteric reimplantation is safe and effective for pediatric patients. It can be applied to patients with VUR and VUJO. Intermediate term result confirmed its reliability and low recurrence rate. It has good potential to become the preferred approach of choice in the future.